Mitsubishi Materials Corporation

Nissan Motor Company Limited

Diamet Corporation

Mitsubishi Kinzoku Kabushiki Kaisha

Mitsubishi Metal Corporation

Jemco Inc.

Ryoji Nakayama

Takuo Takeshita

Muneaki Watanabe

Tamotsu Ogawa

Gakuji Uozumi

Koichiro Morimoto

Makoto Kano

Tetsurou Tayu

Yoshio Kawashita

Katsuhiko Mori

Yoshinari Ishii

Kazunori Igarashi

Yasushi Nayuki

Shouichi Kubo

Hideaki Ono

Munekatsu Shimada

Takae Ono, Legal Representative

Yoshinari Ishill

Norihito Fukatsu

Oxide-coated Fe powder for producing various electromagnetic circuit components requiring high resistivity is provided. The oxide-coated Fe powder is a Mg-containing oxide film-coated iron powder coated with an Mg&#x2014;Fe&#x2014;O ternary-based deposition film at least containing (Mg, Fe)O. The (Mg,Fe)O is a crystalline MgO-dissolving wustite. The Mg&#x2014;Fe&#x2014;O ternary-based oxide deposition film has a sulfur-enriched layer containing a higher concentration of sulfur than that of central portion of the iron powder, fine crystalline texture having a grain size of 200 nm or less, and the outermost surface is substantially composed of MgO. A composite soft magnetic material using the Mg-containing oxide film-coated iron powder is also provided.

Iron powder coated with Mg-containing oxide film

This rare earth magnet having high strength and high electrical resistance has a structure including an R&#x2014;Fe&#x2014;B-based rare earth magnet particleswhich are enclosed with a high strength and high electrical resistance composite layer. The high strength and high electrical resistance composite layeris constituted from a glass-based layerthat has a structure comprising a glass phase or R oxide particlesdispersed in glass phase, and R oxide particle-based mixture layersthat are formed on both sides of the glass-based layerand contain an R-rich alloy phasewhich contains 50 atomic % or more of R in the grain boundary of the R oxide particles.

Rare earth magnet having high strength and high electrical resistance

A method for producing a soft magnetic metal powder coated with a Mg-containing oxide film, comprising the steps of adding and mixing a Mg powder with a soft magnetic metal powder which has been subjected to heating treatment in an oxidizing atmosphere at a temperature of 40 to 500&#xb0; C. to obtain a mixed powder, and heating the mixed powder at a temperature of 150 to 1,100&#xb0; C. in an inert gas or vacuum atmosphere under a pressure of 1&#xd7;10to 1&#xd7;10MPa, while optionally tumbling; and a method for producing a composite soft magnetic material from the soft magnetic metal powder coated with a Mg-containing oxide film.

Method for producing soft magnetic metal powder coated with Mg-containing oxide film

This rare earth magnet having high strength and high electrical resistance has a structure including an R&#x2014;Fe&#x2014;B-based rare earth magnet particleswhich are enclosed with a high strength and high electrical resistance composite layer. The high strength and high electrical resistance composite layeris constituted from a glass-based layerthat has a structure comprising a glass phase or R oxide particlesdispersed in glass phase, and R oxide particle-based mixture layersthat are formed on both sides of the glass-based layerand contain an R-rich alloy phasewhich containsatomic % or more of R in the grain boundary of the R oxide particles.

A rare earth magnet powder has a chemical composition which includes R: 5 to 20% (wherein, R represents one or two or more rare earth elements being inclusive of Y but exclusive of Dy and Tb), one or two of Dy and Tb: 0.01 to 10%, and B: 3 to 20%, with the balance comprising Fe and inevitable impurities; and an average particle diameter of 10 to 1,000 &#x3bc;m, wherein 70% or more of the entire surface of the rare earth magnet powder is covered with a layer being rich in the content of one or two of Dy and Tb and having a thickness of 0.05 to 50 &#x3bc;m.

Rare earth magnet powder and method of producing the same

A flat soft magnetic metal powder is provided that includes: Ni in the range of 60 to 90 mass %, one or more kinds of Nb, V, and Ta in the range of 0.05 to 20 mass % in total (0.05 to 19.95 mass % when Mo is added thereto), Mo in the range of 0.05 to 10 mass % if necessary, one or two kinds of Al and Mn in the range of 0.01 to 1 mass % in total if necessary, and the balance including Fe; an average grain size of 30 to 150 &#x3bc;m and an aspect ratio (average grain size/average thickness) of 5 to 500; and a flat face. Here, with a peak intensity of a face index () in an X-ray diffraction pattern Iand a peak intensity of a face index () I, a peak intensity ratio I/Iis in the range of 0.1 to 10.

Flat soft magnetic metal powder and composite magnetic material including the soft magnetic metal powder

The invention provides an Fe&#x2014;Ni&#x2014;Mo soft magnetic flaky powder having a component composition of, in percent by mass, Ni: 60 to 90%, Mo: 0.05 to 1.95%, and the balance of Fe and unavoidable impurities, and a flat surface of an average particle size of 30 to 150 &#x3bc;m, and an aspect ratio (average particle size /average thickness) of 5 to 500; and having a peak intensity ratio I/Iwithin a range between 0.43 and 10, where Iis the peak height of the face index (200) and Iis the peak height of the face index (111), in an X-ray diffraction pattern measured in such a manner that the plane including the X-ray incident direction and the diffraction direction is perpendicular to the flat surface of the soft magnetic flaky powder, and the angle between the incident direction and the flat surface is equal to the angle between the diffraction direction and the flat surface. Furthermore, the invention provides a soft magnetic flaky powder with oxide layer wherein an oxide layer of a thickness of 50 to 1000 &#x212b; is formed on the surface of this soft magnetic flaky powder.

Fe-Ni-Mo soft magnetic flaky powder and magnetic composite material containing soft magnetic powder

An object of the present invention is to provide a composite soft magnetic sintered material that has high density, high mechanical strength and high relative magnetic permeability at high frequencies and, in order to achieve this object, the present invention provides a method of producing the composite soft magnetic sintered material, which comprises mixing a composite soft magnetic powder, that consists of iron powder, Fe&#x2014;Si based soft magnetic iron alloy powder, Fe&#x2014;Al based soft magnetic iron alloy powder, Fe&#x2014;Si&#x2014;Al based soft magnetic iron alloy powder, Fe&#x2014;Cr based soft magnetic iron alloy powder or nickel-based soft magnetic alloy powder (hereinafter these powders are referred to as soft magnetic metal powder) of which particles arc coated with a ferrite layer which has a spinel structure, with 0.05 to 1.0% by weight of silicon dioxide powder having a mean powder particle size of 100 nm or less and sintering the mixed powder after compression molding, or processing two or more kinds of the composite soft magnetic powders, of which particles are coated with ferrite layer having a spinel structure of a different compositions, by compression molding and sintering.

Composite soft magnetic sintered material having high density and high magnetic permeability and method for preparation thereof

An R--T--M alloy material, wherein R is at least one rare earth metal including Y, T is Fe or an Fe component partially replaced by Co or Ni, M is B or a B component partially replaced by C as primary components is prepared by heating the alloy at a temperature from room temperature to a specific temperature of less than 500.degree. C. in a non-oxidizing atmosphere and holding it at the given temperature, if necessary; performing hydrogenation by holding the alloy in a hydrogen atmosphere or a mixed gas atmosphere of hydrogen and an inert gas at a specific temperature in the range of 500-1,000.degree. C.; medial annealing the alloy by holding the R--T--M alloy after the hydrogenation step in an inert gas atmosphere at a specific temperature in the range of 500-1,000.degree. C.; and dehydrogenating the alloy by holding the alloy in a vacuum of less than 1 Torr for dehydrogenation, and then cooling the alloy.

Method for manufacturing a rare earth magnetic powder having high

A solid resin-coated composite magnet powder for producing an improved anisotropic bonded magnet contains individual anisotropic magnet powder particles each having a surface coated with a solid resin layer thereon. A method is disclosed for producing a solid resin-coated magnet powder, including the steps of kneading an anisotropic magnet powder with a solid resin under a reduced pressure, granulating the resultant mixture to produce a solid resin-coated composite magnet powder, and milling the composite magnet powder produced to separate the solid resin-coated composite magnet powder into individual anisotropic magnet powder particles coated with the solid resin.

Solid resin-coated magnet powder and a method for producing an

The present invention presents a method and an apparatus for heat treating a metallic material by performing hydrogen absorption in or desorption from the metallic material. The method includes the steps of recovering the hydrogen gas released from a desorption step and recycling it to a hydrogen absorbing step. Hydrogen recovering can be performed either in a device containing a hydrogen absorbing alloy or in a second heat treating furnace containing the metallic material. Various controlling devices are used to regulate the process of heat treating and recovering of hydrogen gas.

Method for heat treating metallic materials and apparatus therefor

A magnetically anisotropic R-T-B-M powder material which is starting with an R-T-B-M raw alloy material having a c-axis crystal orientation of an R.sub.2 T.sub.14 B-type intermetallic compound phase. In one embodiment, the starting material is compressed sintered in a magnetic field and recompressed in a magnetic field. In a second embodiment, the starting material is hot-pressed and homogenized. A method of manufacturing anisotropic magnets such as bond and full density magnets made from the magnetically anisotropic R-T-B-M powder material is disclosed.

Method of manufacturing magnetically anisotropic R-T-B-M powder material

The present invention provides a method for producing a rare earth alloy magnet powder exhibiting stable and superior magnetic properties using hydrogenation followed by dehydrogenation. In a method for producing a rare earth alloy magnet powder wherein a homogenized rare earth alloy magnet alloy material is subjected to hydrogenation at a temperature in a range between 750.degree. C. and 950.degree. C., followed by dehydrogenation at a temperature in a range between 750.degree. C. and 950.degree. C.; cooled; and crushed, both the hydrogenation and the dehydrogenation are carried out in a vacuum tube furnace; and the alloy material in the dehydrogenation step maintains a temperature drop of at most 50.degree. C. due to an endothermic reaction which occurs during the dehydrogenation step.

Method for producing rare earth alloy magnet powder

A hot press molded body or an HIP molded body having one of a composition comprising R: 10-20 atomic %, B: 3-20 atomic %, and a total amount of one or a plurality of Ga, Zr, and Hf: 0.001-5.0 atomic %, a remainder comprising Fe and unavoidable impurities; or a composition comprising R: 10-20 atomic %, B: 3-20 atomic %, and a total amount of one or a plurality of Ti, V, Nb, Ta, Al, and Si: 0.001-5.0 atomic %, a remainder comprising Fe and unavoidable impurities; or a composition comprising Co: 0.1-50 atomic % added to one of the above compositions, having an aggregate structure of crystallized grains having as a main phase thereof a R.sub.2 Fe.sub.14 B type or R.sub.2 (Fe, Co).sub.14 B type intermetallic compound having a tetragonal structure, the crystallized grains having dimensions of 0.05-20 .mu.m; and individual crystallized grains comprising more than 50 volume % of the total crystallized grains comprising the aggregate structure, have a value of less than 2 of a ratio b/a of a smallest grain diameter a and a largest grain diameter b.

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Kashiwa, Japan

Ryoji Nakayama